The present invention relates to drawing instruments.
In particular, the present invention relates to drawing instruments which are adapted to be used in connection with inscribing given geometric figures on the surface of a sheet material.
At the present time, geometric figures are drawn on the surface of a sheet material such as paper by the use of a suitable template which takes the form of a sheet of plastic material which has punched therethrough a number of openings of different sizes and having configurations conforming to the particular geometric figures. For example in the case of ellipses such a sheet of plastic will have punched therethrough elliptical openings of various sizes, and of course the draftsman must select one of these elliptical openings as a guide for drawing a given ellipse. Of couse, the same procedures are involved in connection with other geometric figures.
These conventional procedures involve a considerable inconvenience and have relatively large inaccuracies inherent therein inasmuch as the draftsman can only select by eye a suitable opening of the desired configuration and then must position the template so that the selected opening is properly oriented prior to moving his pencil or pen along the edge which defines the selected opening.